[twitch:stream] Clarify channel_id reassignment rationale (#6263)

diff --git a/youtube_dl/extractor/twitch.py b/youtube_dl/extractor/twitch.py
index ab557a1a57f4936b7f93d46269607127324740bf..948c8ce39e6eb4de1fd4c3746af71f2d8d67a7a7 100644 (file)
--- a/youtube_dl/extractor/twitch.py
+++ b/youtube_dl/extractor/twitch.py
@@ -346,6 +346,10 @@ class TwitchStreamIE(TwitchBaseIE):
                 'http://www.twitch.tv/%s/profile' % channel_id,
                 'TwitchProfile', channel_id)
 
+        # Channel name may be typed if different case than the original channel name
+        # (e.g. http://www.twitch.tv/TWITCHPLAYSPOKEMON) that will lead to constructing
+        # an invalid m3u8 URL. Working around by use of original channel name from stream
+        # JSON and fallback to lowercase if it's not available.
         channel_id = stream.get('channel', {}).get('name') or channel_id.lower()
 
         access_token = self._download_json(